Cellulose-ether solvent and composition



Patented Unit. 11?, W22.

warren snares WILLIAHLR. ii O15 ROCHESTER, NEW.YORK, ASSIGNOR TO EASTMANKODAK j COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF YO.

onnaunosn nrnnn sonvnnr Ann COMPOSITION.

Ito Drawing. Application filed April 5,

To all whom it may concern:

Be it known that 1, WILLIAM R. Wane, a citizen of the United States ofAmerica, residing at Rochester, in the county of 5 Monroe .and State ofNew York, have invented certain new and useful Improvements inCellulose-Ether Solvents and Compositions, of which the following is afull, clear, and exact specification.

This invention relates to solvents for making strong solutions ofcellulose ether and also relates to the cellulose ether compositionsproduced by the aid of such solvents. One object of my invention is torovide a solvent which will dissolve such arge proportions of celluloseethers that thick or viscous flowable solutions may be obtained for usein plastic and film making arts. Another object of my invention istoprovide a cellulose ether solution which may be manufactured intostrong, flemhifle, transparent film on the machines and by the methodsnow in use.

In U.' S. Patent No. 1,188,376, Li-lienfeld,

June 20, 1916, there are disclosed a series of alkyl ethers ofcellulose. Certain of these are practically insoluble in water, and myinvention relates, but is not limited, to the ethers having thatproperty. While the ethers form thin solutions in the lower monohydroxyaliphatic-alcohols or ethylene ohlorobromide, it has been found thatsuch single solvents by themselves donot dissolve a sufiicientproportion of the ethers to make a desirably thick flowable compositionor dope, such as may be used in the manufacture of photographic filmbase by customary methods, or in the other plastic arts.

I have discovered that an adequately 40 strong and useful solvent may beprepared by mixing ethylene chlorobromide with one or more of the lowermonohydroxy aliphatic alcohols. By lower monohydroxy aliphatic alcohols,1 include those having less than 6 carbon atoms. F or example, I may usefrom 90 to 1 parts of ethylene 'chlorobromide and 10 to 90 parts byweight of the alcohol, say methyl or ethyl alcohol as an illustration.in the preferred form of my so invention l use equal parts by weight ofethylene chlorobromidaand methyl or ethyl alcohol. While the amount ofether that 1921. Serial Ito 458,751.

may be dissolved in such mixed solvents may be varied as desired over-alarge range,

it is noted, for the sake of example, that 1 part by weight ofwater-insoluble ethyl cellulose when dissolved in 5 parts of one of thedope, such, for instance, as triphenyl or I .tricresyl phosphate,'camphor, etc. In the formation of the film a considerable amount ofethylene chlorobromide is left therein, due to its relatively lowvolatility. It imparts useful properties to such film.

The ingredients are of the ordinary com-.

mercial type and sufficiently purified for the process of filmmanufacture, so as to give a dope yielding films having the properrelative freedom from color. The viscous-flowable dope above describedcan be used in connection with the usual film-forming appa'ratuswithoutthe necessity of expensive alterations in the latter.

Having thus described my invention, i

what I claim asnew and desire to secure by Letters Patent is:

l. A solvent for cellulose ethers, comprising a mixture of ethylenechlorobromide and a monohydroxy aliphatic alcohol.

2. A solvent for alkyl ethers of cellulose, comprising from to 10 partsby weight of ethylene chlorobromide and from 10 to 90 parts by Weight ofa lower monohydroxy aliphatic alcohol.

3. A composition of matter, comprising cellulose ether dissolved in amixture containingethylene chlorobromide and a lower inonohydroxyaliphatic alcohol.

4-. A viscous flowable composition, comprising'an alkyl ether ofcellulose dissolved in a solvent containing from 90 to in parts byweight of ethylene chlorobromide and;

11) to 90 parts of a lower monohydroxy' aiiphatic alcohol.

A composition of matter, comorisin -insolublo ethyl cellulose, eohromide and methyl alcohol. Rochester, New York, this 31st (is; of 1 1

